JP2006521214A - Brazed alloy fixed diamond tool insert and method for manufacturing the same - Google Patents

Abstract

A high abrasive tool material having a carbide side added with a suitable brazing alloy, then the tool material is shaped into a desired tool shape, and the cutting tool is brazed by induction heating. Mold. By using a pre-coated brazing alloy on the tool material for cutting tool forming, it is possible to braze the high abrasive material directly to the tool insert, thereby achieving a prior art process, i.e. In the process of brazing the assembly of the high abrasive tool stock, brazing alloy, and tool insert, minimizing the working and working time required to shape and handle the brazed substrate It is. The brazed material can be conveniently used in an automatic brazing operation for forming a cutting tool.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to US Provisional Application No. 60/445613, filed February 7, 2003.

  The present application relates to a braze alloy coated diamond tool material and a method for producing such a tool material.

  Cutting tools for machining, milling, turning, cutting, or excavation are often provided with an insert of a hard cutting material such as, for example, a high abrasive material. Polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN) are high abrasive materials that are widely used in tool inserts for machining or cutting non-ferrous and ferrous metals, respectively. The tool is manufactured by brazing the PCD / PCBN material (blank) to a tool insert or a tool body (for example, a steel shaft, etc.), and then polishing or forming the final shape with a diamond grindstone. It is common.

  In manufacturing applications, tools using PCD or PCBN materials are usually superior to many common tools in functionality. However, the process of manufacturing a cutting tool from a PCD material or PCBN material is a labor intensive process, and in particular, a brazing operation for joining or bonding a high abrasive material material and a tool insert by a fusion process is labor intensive. The bond strength (adhesive strength) is affected by various factors including a gap between the parts, a brazing material to be used, a joining surface, a brazing state, and the like. In the brazing operation, care must be taken to ensure good adhesion between the high abrasive material and the tool joint surface. Prior to heating, a brazing material is applied or placed on the bonding surfaces. The brazing material can be one of a variety of shapes such as slurry, paste, powder, molded ring, washer, disc, tape, foil, etc., which fits into a groove or pocket inside the contacting carbide surface Is.

  Alloy foil brazing materials include, but are not limited to, excellent flow properties that promote good adhesion ("Advanced Materials & Processes" dated June 2001, "Effective brazing with amorphous foils" Is generally preferred over other shapes for a number of reasons, including sexuality (see "Brazing with amorphous foil perms"). However, the use of brazing foil not only requires careful handling and precise placement of the foil pieces and tool material parts, but also brazing into a shape that matches the cutting tool material. The cost of manufacturing the tool is significantly increased because of the additional labor of cutting the pieces of the alloy foil in a monotonous manner.

  In the brazing process, the brazing material is placed between the tool material and the tool insert (or other tool that brazes the material) and a solvent (flux) material is applied to prevent oxidation. The assembly is heated to a temperature above the melting point of the brazing material. This heat treatment also ensures that the operator pays close attention to the joining surface, i.e. the tool insert, the brazing joint layer, and the tool material, to ensure good adhesion of the joining surface. It is labor intensive because the material must be rearranged. After the tool blank is accurately placed in the pocket and the brazing is sufficiently spread over the entire joint surface, the assembly is cooled to room temperature to complete the brazing operation. In the final stage, the tip of the assembly is polished to the desired tool shape.

  As Carb-I-Tool, a leading manufacturer of precision router tools, shaping tools and cutting tools for workshops, pointed out, “One of the secrets to producing high quality bits is to eliminate bubbles completely. , Brazing the tip of the carbide to the body.Manufacturing by skilled workers is still the best way to ensure (high quality bit) "(http://www.aptoolparts.com/html) /About_us.html).

  Applicant says that before and during the brazing operation to fuse the high abrasive tool material into the tool insert, the brazed substrate must be shaped, cut and handled monotonically enough that the skilled worker is fed up We have found a way to minimize or eliminate some of the time-consuming work steps in prior art procedures. In the method of the present invention, a part of the brazing process is processed “off-line”, that is, a method in which the brazing alloy is previously fixed to the tool material.

  The present invention relates to a high abrasive tool material (blank) having a carbide side coated with a suitable brazing alloy, and further shaping the tool material into a desired tool shape and forming a cutting tool for brazing by induction heating. About.

  The present invention also relates to a method of forming a cutting tool, the method comprising coating a carbide side of a supported high abrasive tool stock with a suitable brazing alloy, and optionally a tool coated with said brazing alloy. Cutting or shaping the blank to the desired shape or exact dimensions to braze the braze alloy coated tool blank into the pocket or tool body of the tool insert.

  As described in the next section, the carbide side of the supporting high abrasive tool material is pre-coated with a suitable brazing alloy before the tool blank (blank) is brazed directly to the tool insert or tool body, or It is fixed. By pre-adhering or coating the carbide side of the tool blank with the brazing alloy, handling of the brazing alloy interface in the brazing process is eliminated. In the process of the present invention, the high abrasive tool material is secured with a suitable brazing alloy and then the brazing alloy coated tool material is brazed into the pocketed tool insert or tool body. Attached.

Providing a High Abrasive Tool Material In the present specification, the “high abrasive tool material” is a configuration of a PCD (polycrystalline diamond) or PCBN (polycrystalline cubic boron nitride) molded body bonded to a sintered metal carbide support. Points to the element. In general, the compact can be characterized as a unitary bonded structure consisting of a sintered polycrystalline mass of abrasive particles such as diamond or cubic boron nitride (CBN). The molded body can be self-adhesive or comprises a suitable adhesive matrix that occupies about 5% to 75% by volume. The adhesive matrix is typically a metal such as cobalt, iron, nickel, platinum, titanium, chromium, tantalum, copper, or alloys or mixtures thereof, or nitride, carbide, boride, transition metal oxide or Ceramic such as a mixture thereof. The adhesive matrix may also contain a catalyst for recrystallization or growth (eg, aluminum for CBN or cobalt for diamond).

  The sintered metal carbide support has tungsten, titanium, tantalum carbide particles, or mixtures thereof, such as about 6 wt% to about 25 wt% binding, such as cobalt, nickel, iron, or mixtures or alloys thereof. Bonded with the agent.

  The forming process of the high abrasive tool material is performed by a high pressure / high temperature (HP / HT) method. In the processing, an unsintered mass of abrasive crystal particles (for example, diamond, CBN, or a mixture thereof) is disposed inside a protective shielding housing disposed in a reaction cell of an HP / HT apparatus. including. If the sintering of diamond particles is intended, as well as forming a pre-formed mass of sintered metal carbide to support the abrasive particles and thereby forming a shaped body support What can be additionally arranged with the abrasive particles in the housing is a metal catalyst. Next, the contents of the cell are processed conditions sufficient to cause intergranular adhesion between adjacent grains of abrasive particles, and optionally, the sintered particles adhere to the sintered metal carbide support. Exposure to sufficient processing conditions. Typically, such HP / HT treatment conditions are those that are placed at a temperature of at least 1000 ° C. and a pressure of at least 20 Kbar for about 3 to 120 minutes.

  High abrasive materials are commercially available from the General Electric Company under the trade names COMPAX, BZN and Stratapax. In one embodiment, the carbide support tool blank is in the form of a disc having a diameter in the range of about 10 mm to 74 mm.

Pre-fixation of high abrasive tool stock with brazing alloy In one embodiment of the present invention, the tool stock is pre-coated or fixed with a brazing alloy before being shaped or shaped into the desired shape.

  In the present invention, various brazing alloy compositions, for example, brazing alloy compositions as described in Kirk-Othmer's Encyclopedia of Chemical Industry (3rd Edition, Volume 21, page 342 et seq.). Things can be used. The alloy composition for brazing may contain silicon or boron that acts as a melting point reaction inhibitor.

  In one embodiment, the brazing alloy contains valuable metals such as silver, gold and palladium in combination with other metals such as copper, manganese, nickel, chromium, silicon and boron. In another embodiment, the brazing alloy is about 78 wt.% To about 99.97 wt.% Of the first metal (such as silver), about 0.01 wt.% To about 12 wt. It has a weight percent second metal (such as copper), about 0.01 weight percent to about 5 weight percent third metal (such as nickel), and about 0 weight percent to about 5 weight percent silicon. In yet another embodiment, the brazing alloy comprises 78% to 99.97% silver, 0.01% to 12% copper, 0.01% to 5% nickel, and optionally 0.01 % To 5.0% silicon.

  Brazing alloys include, but are not limited to: a) 0.0005 inches to 0.003 inches thick or commercially available from various suppliers such as Wesgo, Allied Signal, and Vita More foils, b) wire, c) powder, d) paste, e) slurry (metal powder, binders such as polyethylene oxide and various acrylics, or solvent-based binders, and selection It can be applied in various shapes, including a solvent.

  Methods for applying or adding a brazing alloy to the carbide side of a supported high abrasive tool stock include, but are not limited to: (a) melt coating, ie, Applying a liquid brazing alloy and solidifying it in place as a uniform layer, b) electroless plating, c) electroplating, d) sputter coating or other physical vapor deposition, e) chemical vapor deposition F) Laser welding, tack welding or spot welding of foil brazing alloys, g) Method of brushing or applying as a paint or paste with a suitable binder, h) Appropriate foil brazing alloys Binding agents, or Sulzer-METCO, Inc., well known in the art. I) flame spraying, j) hot compression (hot pressing) or hot rolling, k) cold compression (cold pressing) or cold rolling, and l) Dip coating with tin-plated or melted brazing alloy.

  In one embodiment, a sufficient amount of brazing alloy is applied or added to the carbide side of the high abrasive material to ensure good adhesion of the material and tool insert during the brazing operation. In another embodiment, the thickness of the brazing alloy applied is the thickness of the foil made of the mixture used as the brazing material, for example 30-150 μm.

After the desired brazing alloy in the shape of the desired tool stock has been applied to the high abrasive material, the brazing alloy coating material is optionally placed in the final for placement in the pocketed insert or tool body. May be machined into a desired shape, for example, an 80 ° triangle with a blade length of 5.0 mm.

  The shape can be formed by various methods known in the art including electric discharge machining (EDM), electric discharge grinding (EDG), laser, plasma and water jet. In one embodiment, the material that has been pre-fixed with the brazing alloy is shaped by an abrasive water jet process. In another embodiment, the surface of the material is laser etched at a predetermined location on the surface or according to a defined mold controlled by a computer to ultimately form the desired shape.

Brazing to Tool Inserts As used herein, “tool insert” or simply “tool” is used to indicate a tool body, tool block or other tool to which the high abrasive material is brazed. Is done. Each tool insert optionally has a pocket for receiving a brazed high abrasive material. In the final step of the present invention, the shaped material is brazed directly onto a pocketed tool insert, such as a steel shaft.

  Brazing can be done in a variety of technical ways, including immersion brazing, in-furnace brazing, brazing by torch heating, brazing by induction heating, and brazing by resistance heating. The brazing temperature is usually in the range of about 525 ° C to about 1650 ° C, depending somewhat on the type of brazing alloy used.

  In one embodiment, brazing is rapid heating (depending on the size of the tool, but may take only a few seconds to complete the brazing), uniform finish, local area of the joint using induction coils For heating, it is performed by induction heating.

  The brazing solvent (flux) is used to dissolve the oxide formed on the surface in the final step of brazing the material pre-fixed with the brazing alloy into the pocketed insert or tool. is there. This solvent may be in the form of a paste or powder.

  By using a braze alloy that has been pre-coated or secured to the carbide support of the high abrasive tool material, the process of brazing the material to the tool insert or tool body can be accomplished with a much smaller amount of solvent. That is a noteworthy point. Further, by pre-adhering the brazing alloy to the high abrasive material, the brazing process is significantly simplified since there is no need to handle and precisely place small pieces of brazing foil.

Use of brazed alloy-fixed high abrasive material for automatic brazing operations Applicants may significantly accelerate automatic brazing operations by using brazed alloy-fixed high abrasive tool materials, That is, it has been discovered that by using a fixture to braze or insert the tool stock and tool body, little or no operator intervention is required. In one embodiment of the present invention, the pre-brazed high abrasive tool stock is used for work with an automatic brazing machine, which is disclosed in US Pat. No. 5,125,555 “Automatic Brazing with Sensing Device”. In line with the apparatus disclosed in “Automatic brazing welding machine with sensor” (where the brazing is performed by the flame heating method).

  In another embodiment of the automated process using the brazed alloy bonded material of the present invention, the brazed coated material 2 is cut into the desired shape (eg, triangle, block, etc.) as shown in FIG. After being shaped, it is placed on a tray 12 carrying a plurality of pockets 1. The pocketed carbide insert is also placed in a separate tray 20 with a plurality of pockets, which is also placed in the brazing machine. Tray 12 and tray 20 are mounted on a spindle or conveyor system that automatically and continuously feeds the brazing machine, the tray advances the pockets one at a time, brazed coated material and corresponding carbide The insert is fed into a worktable heated by induction.

  As the tray advances the pockets one at a time, the optional cover tape 3 is simultaneously peeled from the pockets to expose the braze-coated material 2 or the corresponding insert. In the brazing process, a rotary arm conveyor, robot arm, or similar mechanical means is installed in the subsequent part of the flow operation to accurately place the pocketed carbide insert on the induction heated workbench. The rotary arm (or the second rotary arm) grabs the brazed coated material 2 and places it in the pocket 1 of the heated insert. The temperature of the induction heating is automatically lowered after a predetermined time has elapsed, i.e. after the brazing alloy has melted and the rotary arm has automatically moved the brazed insert. Is repeated until all tool inserts are brazed.

  In one embodiment of the automatic brazing process of the present invention using a brazed material (or a material that has been pre-fixed or coated with a brazing alloy), before brazing, the insert with each pocket is brazed. There is no need to manually apply or paste the brazing alloy foil, and there is no need to manually assemble the insert-brazing-material sandwich and mount it on the brazing machine. It should also be noted that it is not necessary to carefully cut the brazing foil into a shape that matches the joint surface to be brazed.

EXAMPLES The following examples, and the examples generally illustrated in FIGS. 1 and 2, serve only to illustrate the present invention, and the present invention is limited by the following examples. It is not a thing.

Example 1 This example uses a carbide supported polycrystalline diamond (“PCD”) tool stock of 58 mm diameter. The tool material is manufactured by GE Superbrasives, Inc. under the trade name GE Compax 1500. (Worthington, Ohio). The tungsten carbide side of the PCD material is polished with garnet grit spray and washed with isopropanol. Standard brazing alloy foil (Ag (silver) 49%, Cu (copper) 16%, Zn (zinc) 23%, Mn (manganese) 7.5%, Ni (nickel) 4.5%) in diameter Cut into a 58 mm disc and place on the carbide surface of the PCD material. The assembly is then coated with a suitable solvent (flux) material to prevent oxidation and induction heated above the melting point of the alloy (˜650 ° C.). When the brazing is sufficiently liquefied, induction heating is stopped and the material is cooled to room temperature. The brazing alloy adheres well to the carbide surface during the solidification process. Next, the brazed coated tool is polished by garnet grit injection, and the material is cut into several types of tool material shapes by wire EDM.

  FIG. 1 shows a cross-sectional view of the braze-coated tool stock of Example 1. As can be seen from the drawing, the alloy layer uniformly covers the carbide surface and the joint surface appears to be well bonded and continuous.

Example 2 In this example, a molded body coated with the brazing alloy of Example 1 is brazed by induction heating in a vacuum to form a final cutting tool. It is noted that this coated alloy easily wets the carbide support and provides a high strength cutting tool tip suitable for use. In addition, the brazing process is significantly simplified and speeded up more than expected in the prior art process, i.e., the brazing process using a brazing alloy substrate as the material for the bonding surface. It is a point that attracts attention.

  FIG. 2 is a photograph of the tool of Example 2, ie, a brazed coated PDC material after being brazed to the tool. As can be seen from the drawing, the alloy layer uniformly covers the carbide surface, thereby ensuring excellent adhesion.

EXAMPLE 3 The same kind of brazing foil and PCD disk used in Example 1 are mechanically joined by a cold press method. In order to promote the mechanical adhesion of the brazing foil, an oblique parallel line pattern is formed on the carbide surface of the PCD material by wire electric discharge machining (EDM). On the surface of the carbide, two sets of vertical lines are machined to form an oblique parallel line pattern. Each line in the set is 0.010 inches deep and 0.030 inches wide. These lines run parallel to each other and are spaced 0.035 inches from center to center. The second set of lines is formed by rotating the PDC material by 90 degrees with respect to the wire EDM and repeating the same pattern.

  Next, a standard brazing alloy foil having a thickness of 0.005 inches (Ag (silver) 49%, Cu (copper) 16%, Zn (zinc) 23%, Mn (manganese) 7.5% , Ni (nickel) 4.5%) is cut into a disk having a diameter of 58 mm and placed on the carbide surface of the PCD material. The foil is then pressed onto the carbide surface using a Carver laboratory press at a pressure of 10,000 Ibs. After pressing, the foil is deformed into a shape that matches the grooves of the oblique parallel line pattern, thereby mechanically adhering to the PCD material.

  Although the present invention has been described with reference to preferred embodiments, those skilled in the art will appreciate that various modifications can be made to the elements without departing from the scope of the invention and equivalents can be substituted. Will. All citations referred to herein are expressly incorporated herein by reference.

FIG. 1 is a photograph showing an EDM cut surface of one embodiment of the material of the present invention after coating with a brazing alloy. FIG. 2 is a photograph of one embodiment of the brazed coated PCD material of the present invention after brazing to the tool body. FIG. 3 shows a diagram in which the brazing material of the present invention is used in an automatic brazing process as part of the supply tray entering the brazing operation.

Claims (20)

  A material (blank) used for a tool insert, which has a polycrystalline formed body bonded to a sintered carbide support, and the sintered carbide support is added with a brazing alloy.   2. The material according to claim 1, wherein the polycrystalline formed body has a hard sintered body containing cubic boron nitride, diamond, or a mixture thereof. 2. The material of claim 1 wherein the sintered carbide support is added with a brazing alloy by a method selected from one of the following.
a) a method of melt-coating the brazing alloy onto the carbide support;
b) a method of electroless plating the brazing alloy on the carbide support;
c) a method of electroplating the brazing alloy onto the carbide support;
d) a method of sputter coating the brazing alloy on the carbide support;
e) a method of physical vapor depositing the brazing alloy onto the carbide support;
f) a method of chemical vapor depositing the brazing alloy onto the carbide support;
g) a method of spot welding the brazing alloy to the carbide support as a brazing foil;
h) a method of brushing the carbide support with a suitable binder as a paint or paste as the brazing alloy;
i) A method of sticking the foil-like brazing alloy to the carbide support with an adhesive tape,
j) flame spraying the brazing alloy onto the carbide support;
k) A method in which the brazing alloy is heat-compressed (hot pressed) onto the carbide support as a brazing foil,
l) A method of cold-pressing the carbide support as a brazing foil to the carbide support,
m) A method of dip-coating the carbide support on the molten brazing alloy.   2. The high abrasive material of claim 1, wherein the sintered carbide support comprises about 78-99.97% silver, about 0.01-12% copper, 0.01% -5% nickel, and selection. In particular, the sintered carbide support is added with the brazing alloy by coating with an alloy having a composition having about 0.01-5.0% silicon.   2. The high abrasive material of claim 1, wherein the sintered carbide support is added with a brazing alloy in the form of a slurry, paste, powder, ring, washer, disc, tape, or foil.   6. The high abrasive material of claim 5, wherein the brazing alloy is a foil having a thickness in the range of 0.0005 inches to 0.003 inches.   A material used for a tool insert having a polycrystalline formed body bonded to a sintered carbide support added with a brazing alloy, the carbide support added with the brazing alloy of the material The body is the material that is brazed directly onto the tool insert in the brazing process. 8. The material of claim 7, wherein the sintered carbide support is added with a brazing alloy by a method selected from one of the following.
a) a method of melt-coating the brazing alloy onto the carbide support;
b) a method of electroless plating the brazing alloy on the carbide support;
c) a method of electroplating the brazing alloy onto the carbide support;
d) a method of sputter coating the brazing alloy on the carbide support;
e) a method of physical vapor depositing the brazing alloy onto the carbide support;
f) a method of chemical vapor depositing the brazing alloy onto the carbide support;
g) a method of spot welding the brazing alloy to the carbide support as a brazing foil;
h) a method of brushing the carbide support with a suitable binder as a paint or paste as the brazing alloy;
i) A method of sticking the foil-like brazing alloy to the carbide support with an adhesive tape,
j) flame spraying the brazing alloy onto the carbide support;
k) A method in which the brazing alloy is heat-compressed (hot pressed) onto the carbide support as a brazing foil,
l) A method of cold-pressing the carbide support as a brazing foil to the carbide support,
m) A method of dip-coating the carbide support on the molten brazing alloy.   8. The material of claim 7, wherein the sintered carbide support comprises 78-99.97% silver, 0.01-12% copper, 0.01% -5% nickel, and optionally 0.8. The sintered carbide support is added with the brazing alloy by coating with a brazing composition having 01-5.0% silicon.   10. The material of claim 9, wherein the sintered carbide support is added with a brazing alloy in the form of a slurry, paste, powder, ring, washer, disk, tape, or foil.   The material of claim 10, wherein the brazing alloy is a foil having a thickness in the range of 0.0005 inches to 0.003 inches.   A method for manufacturing a cutting tool, comprising a step of brazing a material having a polycrystalline formed body bonded to a sintered carbide support added with a brazing alloy to a tool insert. 13. The method of claim 12, further comprising:
Before brazing the material to the tool insert, the step of configuring the material into a shape that allows the material to be accurately positioned in the tool insert.   14. The method of claim 13, wherein the step of forming the material uses one of electric discharge machining, electric discharge grinding, laser, plasma, water jet, and combinations thereof.   In a cutting tool having a tool insert and a material, the material has a polycrystalline formed body bonded to a sintered carbide support added with a brazing alloy. 16. The cutting tool of claim 15, wherein the sintered carbide support is added with a brazing alloy by a method selected from one of the following.
a) a method of melt-coating the brazing alloy onto the carbide support;
b) a method of electroless plating the brazing alloy on the carbide support;
c) a method of electroplating the brazing alloy onto the carbide support;
d) a method of sputter coating the brazing alloy on the carbide support;
e) a method of physical vapor depositing the brazing alloy onto the carbide support;
f) a method of chemical vapor depositing the brazing alloy onto the carbide support;
g) a method of spot welding the brazing alloy to the carbide support as a brazing foil;
h) a method of brushing the carbide support with a suitable binder as a paint or paste as the brazing alloy;
i) A method of sticking the foil-like brazing alloy to the carbide support with an adhesive tape,
j) flame spraying the brazing alloy onto the carbide support;
k) A method in which the brazing alloy is heat-compressed (hot pressed) onto the carbide support as a brazing foil,
l) A method of cold-pressing the carbide support as a brazing foil to the carbide support,
m) A method of dip-coating the carbide support on the molten brazing alloy. A unit (set of equipment) used in an automatic brazing machine to form a cutting tool,
a) a plurality of materials, each material having a polycrystalline compact bonded to a sintered carbide support, wherein the sintered carbide support is added as a brazing alloy; ,
b) A plurality of inserts (a set of equipment) having a plurality of inserts, each insert having a pocket for receiving each material.   18. The unit of claim 17, wherein the sintered carbide support is added with a brazing alloy in the form of a slurry, paste, powder, ring, washer, disk, tape, or foil. A method of continuously brazing a tool insert to form a cutting tool comprising:
a) placing a material having a polycrystalline compact bonded to a sintered carbide support in a pocket in a tool insert, wherein the sintered carbide support is added with a brazing alloy; And a process of
b) subjecting the material placed in the pocketed insert to sufficient thermal energy to melt the brazing alloy;
c) recovering the material brazed therein,
d) repeating steps a) to c) for each tool insert.   20. The method of claim 19, wherein the sintered carbide support is added with a brazing alloy in the form of a slurry, paste, powder, ring, washer, disc, tape, or foil.

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